Field of the Invention
The present invention relates to an image stabilization apparatus.
Description of the Related Art
An image stabilization apparatus is configured to detect a vibration of an image-pickup apparatus using a vibration detector, and moves an image stabilization lens or an image sensor in a direction orthogonal to the optical axis according to a detection result. A vibration signal output from the vibration detector contains a signal caused by a panning/tilting operation in addition to a signal caused by a manual vibration. When the image stabilization is simultaneous with the panning/tilting operation, a new image vibration (revibration) occurs after the panning/tilting operation ends. As a result, a user feels uncomfortable in the camera operation and captured image.
Accordingly, it has been conventionally proposed to stop the image stabilization during the panning/tilting operation and to resume it after the panning/tilting operation. Japanese Patent Laid-Open No. (“JP”) 2006-113264 proposes an image stabilization apparatus configured to decrease a cutoff frequency step by step after the panning/tilting operation in accordance with an angular velocity signal representative of the camera vibration that does not instantly becomes zero and gradually approaches to zero.
Due to a time constant, a filter having a low cutoff frequency needs a long time for the steady state necessary for a desired performance. The steady state can be obtained more quickly by switching the cutoff frequency stepwise as in JP 2006-113264. However, when a large vibration occurs while the cutoff frequency is being switched, the method according to JP 2006-113264 cannot fully remove a vibration amount at the switching end timing. When this signal is used for a signal captured in exposure, the quality of the captured image degrades due to the vibration.